A heavy snowfall season means good skiing (Lind and Sanders, 2004, describe the physics of skiing), snowshoeing, tobogganing, and beautiful winter scenery. It also means a lot of snow clearance on our side walks and car parks, expensive snow plowing to clear our roads, terrible traffic conditions, driving hazards, and occasionally, flooding during spring snowmelt seasons. Snowfall is a primary factor in disrupting transportation on highways, in cities, and at airports. In January 2008, for example, heavy snows in southeastern China caused widespread disruption to road and rail traffic, 17 deaths, and the collapse of 3,635 houses in Anhui province under the weight of snow. The amount of water that would yield 10 mm of rain can produce 5–10 cm or more of snow. Even 5 cm of snow is enough to create disruptions to traffic. This is particularly true in places where snowfall is uncommon, but heavier falls can also occur (e.g. Atlanta, Seattle, London, Canberra, Vancouver).